I have a home internet connection that is a resold AT&T U-Verse connection. I doubt any of these fixes are available to me -- the extremely user-hostile equipme

I have a home internet connection that is a resold AT&T U-Verse connection. I doubt any of these fixes are available to me -- the extremely user-hostile equipment provides essentially no user-configurable options, and I have been told it has no switched mode, not even a secret one. So there's no way I can introduce my own router hardware unless I want to be double-NATted. (Also, it has a broken caching DNS server, and forces that broken server into its DHCP responses; the server it returns is not user-configurable.) So what's an ordinary consumer to do?